Development of novel strategies to deflect or ameliorate influenza infection will be greatly facilitated by a broader understanding of the cell-autonomous molecular components that are subverted to support viral infection, and those that are mobilized to defend against it. The advent of genome-wide siRNA libraries, coupled with one-well/one-gene high throughput screening strategies, provides the opportunity to generate experimental platforms to derive unbiased comprehensive collections of validated gene targets that support critical biological systems. Our approach is to apply genome-wide RNAi-based somatic cell genetics for an extensive and unbiased identification of gene products in human bronchial epithelial cells that support 1) the influenza life cycle and 2) the antiviral surveillance and response system. In Specific Aim 1, a genome-wide siRNA screen will be leveraged to identify all gene depletions that deflect (resistor loci) or promote (sensitizor loci) bronchial epithelial cell death upon exposure to influenza A/WS/33. In Specific Aim 2 a focused hierarchical experimental strategy will be employed to parse validated hits into functional complementation groups representing key biological processes. The resulting molecular annotation of critical biological pressure points controlling flu replication and deflection of host innate immune pathway activation will be used to help 1) generate novel mechanistic insights into the host/virus relationship, 2) broaden knowledge of targetable biological pressure points in host systems that support viral replication, and 3) facilitate identification of the molecular targets of novel bioactive compounds with drug-like properties. Influenza virus must hijack proteins present within the cells of the human mucosa in order to reproduce in infected individuals. A detailed understanding of the mucosal cell proteins required to support viral replication as well as those which are mobilized to defend against it will aid development of novel therapeutic and preventative interventions. The work described here will help produce a comprehensive knowledge base of the mucosal cell proteins that both support and antagonize influenza A infection and replication.